Biggest Bitcoin Exchange Restores Service

Bitstamp, the manager of the world's largest bitcoin exchange, said Saturday it had restored automated customer withdrawals, after they were halted for four days because of a hacking attack that crippled various platforms for exchanging the digital currency and raised questions about the security of its global network.

Separately, Tokyo-based Mt. Gox, whose struggle with fraudulent customer requests paved the way for a networkwide...